<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>判断成绩案例</title>
    <script>
        var one = prompt('请输入您的分数')
        if (one >= 80) {
            alert('你很优秀')
        }
        else if (60 <= one && one < 80) {
            alert('你还需努力')
        }
        else {
            alert('你可能不太适合学习')
        }
    </script>
</head>
<body>
    
</body>
</html>